Arctic summer wind shift could affect sea ice loss and U.S./European weather, says NOAA-led study

Changes in summer Arctic wind patterns contribute not only to an unprecedented loss of Arctic sea ice, but could also bring about shifts in North American and European weather, according to a new NOAA-led study published today in Geophysical Research Letters.

A research team led by James Overland, Ph.D., of NOAA’s Pacific Marine Environmental Laboratory in Seattle, Wash., examined the wind patterns in the subarctic in the early summer between 2007 and 2012 as compared to the average for 1981 to 2010. They discovered that the previously normal west-to-east flowing upper-level winds have been replaced by a more north-south undulating, or wave-like pattern. This new wind pattern transports warmer air into the Arctic and pushes Arctic air farther south, and may influence the likelihood of persistent weather conditions in the mid-latitudes.

“Our research reveals a change in the summer Arctic wind pattern over the past six years. This shift demonstrates a physical connection between reduced Arctic sea ice in the summer, loss of Greenland ice, and potentially, weather in North American and Europe,” said Overland, a NOAA research oceanographer.  

The shift provides additional evidence that changes in the Arctic are not only directly because of global warming, as shown by warmer air and sea temperatures, but are also part of an “Arctic amplification” through which multiple Arctic-specific physical processes interact to accelerate temperature change, ice variability, and ecological impacts.

The study, entitled “The Recent Shift in Early Summer Arctic Atmospheric Circulation,” was co-authored by scientists from Rutgers University in New Jersey,  the University of Sheffield in the United Kingdom, and the Joint Institute for the Study of the Atmosphere and Ocean, a partnership of NOAA and the University of Washington. It can be found online.

http://www.noaanews.noaa.gov/stories2012/20121010_arcticwinds.html